Monoazo dyestuffs



Patented Apr. 25,1950

MONOAZO DYESTUFFS Willy Widmer, Bottmingen, and Heinrich Zollinger, Basel, Switzerland, assignors to Ciba Limited, Basel, Switzerland, a Swiss firm No Drawing. Application May 5, 1947, Serial No. 746,156. In Switzerland May 31, 1946 3 Claims. (Cl. 260-199) According to this invention valuable new monoazo-dyestuffs are made by coupling a diazotized 2-amino-5-acylamino-1:1-diphenyl sulfone in an acid medium with a 2-alkylaminoor a 2-hydroxyalkylamino 8 hydroxynaphthalene 6 sulfonic acid containing in the alkylor hydroxyalkyl radical up to six carbon atoms.

The phenyl radical of which the 1'-position is bound to the SO2-group in the 2-amino-5-acylamino-lzl diphenyl sulfones used as starting materials may be free from substituents or may contain substituents. As such substituents there come into consideration, for example, alkyl groups such as methyl groups, halogen atoms such as bromine and especially chlorine, alkoxy groups such as methoxy groups, and the like. The acylamino group present in the -position of the 2- amino-5-acylamino-1:1'-dipheny1 sulfones may be for example, an amino group containing an aliphatic acyl radical such as a propionylamino group or an acetylamino group, or an amino group containing an aromatic acyl radical especially a benzoylamino group. In the latter case the benzoyl radical may be free from further substituents or it may contain substituents. As such substituents there may be mentioned for example halogen atoms such as bromine and especially chlorine atoms, nitro groups, alkyl groups such as ethyl and especially methyl groups, alkoxy groups such as ethoxy and especially methoxy groups, and the like.

The 2-amino-5-acylamino-1:1-diphenyl sulfones used as starting materials are in part known and in part new, and can be obtained, for example; by known methods from the appropriate 2:5-diamino-1:1'-dipheny1 sulfones by monoacylation with the-usual acylating agents, for exam-.

ple, acidanhydrides or acid halides.

As examples of Z-aminmS-acylamino-l:1'-diphenyl sulfones which can be made by such methods and used as diazo-components in the invention the following may be mentioned: 2- amino-5-benzoylamino-1:1'-diphenyl sulfone, 2- amino-5-benzoy1amino-4'-methyl 1 :1'-diphenyl sulfone, 2-amino-5-(3"-nitrobenzoylamino) 4- methyl-l :1'-diphenyl sulfone, 2-amino-5- (4"- nitrobenzoylamino) 4'-methyl 1:1 diphenyl sulfone, 2-amino-5- (4"-methoxybenzoylamino) 1:1-diphenyl sulfone, 2-amino-5-(2"-chl0rbenzoylamino)-1:1'-diphenyl-sulfone, 2 amino-5- (4"-chlorbenzoylamino) 1:1 diphenyl sulfone and 2 -amino-5-acetylamino-4'-methyl 1:1-diphenyl sulfone.

The alkyl radical in the 2-alkylamino-8-hydroxynaphthalene-6-su1fonic acids used as starting materials may be a methyl, ethyl, propyl, butyl, isobutyl, isoamyl or hexyl radical. If a 2- hydroxyalkylamino 8 hydroxynaphthalene-6- sulfonic acid is used as starting material it may be for example Z-(fi-hydroxyethylamino)-8-hydroxynaphthalene-G-sulfonic acid or 2-(pz'y-dihydroxypropylamino) l 8 hydroxynaphthalene- 6-sulfonic acid.

' The diazotization of the 2-amino-5-acylamino- 1:1-diphenyl sulfone may be carried out by methods usual for compounds which are difficult to diazotize, for example, by means of nitrosylsulfuric acid. As a rule it is of advantage to separate the diazo-compound, for example, by dilution with water and filtration, and to couple the filter cake with a suspension of the 2-alkylaminoor 2 hydroxyalkyla-mino 8 hydroxynaphthalene-fi-sulfonic acid. The 2-alkylaminoor 2- hydroxyalkylamino-S hydroxynaphthalene 6 sulf-onic acids used as coupling components are advantageously first converted into a mono-alkali salt, and then reconverted into the free acids, for example, by the addition of acetic acid. Coupling is conducted in an acid medium, advantageously a medium rendered weakly acid to Congo with acetic acid. Thus, for example, the precipitated and filtered diazo-compound may be coupled with a suspension of the coupling component rendered weakly acid to Congo, and then the free mineral acid already present and also that which is formed during the coupling reaction neutralized, for example, with sodium acetate, and, if desired, the temperature may be raised somewhat. The coupling mass may be worked up in the usual manner in itself known, for example, by neutralization with sodium carbonate, separation by filtration, and drying.

The dyestuffs obtainable by the invention are new and in the form of the free acids correspond to the general formula in which R2 and R3 represent radicals of the henzene series, the radical R3 containing the SO2R2 group in ortho-position with respect to the azo-group and the -NI-I-acyl group in paraposition thereto, and in which R4 represents ther dyestuffs obtainable from various 2-amino- 5-acylamino-1: l-diphenylsulfones as diazo-components and 2-methyl-amino-8-hydroxynaphthalene-G-sulfonic acid by the process of this example:

.. Tint of the dye- Diaz'o-compor'ient Olitaii'iaDle fro'mia? ing on wool from p an acetic acid bath e l 2 a m in o be n to y l a min 0- 2'z5-diai'nino-l:l-diphenyl sulfone 197-198 reddish violet.

1:1-diphenyl sulfone. and benzoyl chloride. 2 2 amino (3 n i t r o b on zo 2:5-d1amino 4-'methyl7l l-dipl1enyl 207-210 brownish violet.

ylaminmi methylu:l-diplienyl sulfone and 3-nitrobenzoyl chlosulfone. ride. 3 2-amino-'(4!=nitrobenzoylamino) 4 .2:5-diamino 4-nicthyl+1: l'-diphenyl 228-230 Do.

methyl-1:1 -dipheuyl sulfone. s gione and 4-nitrobenzoyl chlono. 4 zanlino-(4"-rnethoityhenzoylamino) 2:5-d1amino-1:l-diphenyl sul f one 176-177 bluish violet.

1:1-diphenyl sulfone'. and 4-n1ethoxybenzoyl chloride. 5 2-an1ino-(2"-chlorbenzoylamino)-1:1- 2:5-diamiuo-1:l-diphenyl sulfone 190-l9i Do.

diphenyl sulfone. and 2-chlorbenzoyl chloride. 6 2-amind(4-chlorbenzoylamino)-1:1- 2:5-diamino-l:l-dipheuyl sulione 174-176 D0.

diphenyl sulfone. and 4-chlorbenzoyl chloride.

Example 2 an alkyl or a hydroxy-alkyl radical, containing up to six carbon atoms.

These dyestuffs are suitable for dyeing or printmg a very Wide variety of materials, especially those of animal origin such as leather or silk and principally for dyeing or printing various artificial fibers, for example, animalized artificial silk, superpo'lyainides or superpolyurethanes, etc.

As compared with the known dyestuffs (see, for example, U. 55. Patent No. 1,359,969) of similar constitution which are obtained by coupling diazotized N monoacyl-derivatives of phenylene diamine aryl suliones with 2-aniino 8-hydroxynapthalene-fi-sulfonic acids or N-aryl derivatives thereof in an acid medium, and which are distinguished by the good fastness properties of their dyeings on wool, the dyestuffs obtainable by the present inventionare in many cases distinguished by the unexpected advantage of improved solubility, while in other respects possessing the good fastness properties of the aforesaid known products.

The following examples illustrate the inventidn, the parts being by weight:

Example 1 of an excess of acetic acid. The dia-zo-compo-und is triturated with this paste. After a short time the whole is diluted with 200 parts of water, and the free sulfuric acid is gradually neutralized at a moderately raised temperature by means of sodium acetate solution. When the coupling is complete, the whole is neutralized with sodium carbonate, and the dyestuff is separated by filtration and dried. It is a dark powder which dissolves in Water with aviolet coloration and dyes wool from an acid bath fast reddish violet tints.

In the following table are described a few fur- The separated and filtered diazo-compound obtained from 33.6- parts of 2-amino-5-benzoylaminoA methyl-i 1 -diphenyl-su1fone by the procedure of Example 1 is triturated with 29.5 parts of 2-butylamino-8-hydroxynaphthalene-6- sulfonic acid (obtained by pasting the latter acid with 135 parts of caustic soda solution and 10 parts of water and liberating the free acid from the resulting sodium salt by means of acetic acid). After a short time the Whole is diluted with 200 parts of Water, and the free sulfuric acid is gradually neutralized at a moderately raised temperature b means of sodium acetate solution. When the coupling is complete, the whole is neutralized with sodium carbonate, and the dyestuff is separated by filtration and dried. A dark, bluish powder is formed which dissolves in water with a.

violet coloration and dyes wool from an acetic acid bath somewhat reddish violet tints having excellent properties of fastness.

A dyestufi having very similar properties is obtained from 2-isobutylamino-8-hydroxynaphthalene-6-sulfonic acid.

By using 2-amino-5-acetylamino-4-methyl-l: l'-diphenyl-sulfone as diazo-component, instead of 2-amino-5-benzoylamino-4-methyl-1 :1-diphenyl sulfone, a dyestuii is obtained which dissolves in Water with a violet coloration and dyes animal fibers from a sulfuric acid bath reddish violet tints havin good properties of iastness.

Similar dyestufis are obtained by coupling 2'- amino- 5 -benzoylamino-4='-methyl 1 :1 -diphenyl sulfone with 2-ethylamino-8-hydroxynaphthalene 6-sulfonic acid or with 2- (fihydroxyethylamino)' 8 hydroxynaphthalene 6 sulfonic acid by the procedure described in this example.

Example 3 2 parts of the dystuif obtainable as" described in the first paragraph of Example 1 are dissolved in 4000 parts of water, 10 parts of crystalline sodium sulphate are added; and parts of wool are entered at40-50 C. 3 parts of acetic acid of 40 per cent. strength are then added, the bath is brought to the-boil in the course of hour, and dyeing is carriedon at that tempera-- goods a fast red-violet dyeing is obtained.

6 What we claim is: 3. The. monoazo-dyestuff of the formula,

1. A monoazo-dyestuff which in the form of O OH3 the free acid corresponds to the general formula I N H0 1' 'I no It NH CH' 1 NHOH:

in which :0 stands for a member selected from WILLY WIDMER. the group consisting of hydrogen and methyl, HEINRICH ZOLLINGER. y stands for a member of the group consisting of hydrogen, halogen, alkyl, alkoxy and nitro groups. REFERENCES CITED The monoazmdyestufi of the formula The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,359,969 Montmollin Nov. 23, 1920 00 1,840,385 Clingestein Jan. 12, 1932 g 1,879,261 Hoyer Sept. 27, 1932 1,901,515 Hentrich Mar. 14, 1933 2,053,817 Felix Sept. 8, 1936 2,361,481 Kvalnes Oct. 31, 1944 O 2,374,158 Knight Apr. 17, 1945 N NH-CHI Certificate of Correction Patent No. 2,505,268 April 25, 195.0

WILLY WIDMER ET AL. v

It is hereby certified that errors appea r in the above numbered petent requiring correction as follows:

In the grant, line 2, name of co-inventor, for Zolinger read Zollinger; and in the printed specification, column 8, line 39, for napthalene read naphthalene;

[SEAL] THOMAS F. MURPHY,

Assistant Uommz'ssz'oner of Patents. 

1. A MONOAZO-DYESTUFF WHICH IN THE FORM OF THE FREE ACID CORRESPONDS TO THE GENERAL FORMULA 